As a con­trib­u­tor to the encycli­cal, I read it quite dif­fer­ently. A key quote is that a “rev­o­lu­tion is needed to com­bat cli­mate change” because the world “is begin­ning to look more and more like an immense pile of filth.” Here the encycli­cal is call­ing for an invest­ment in and a mobi­liza­tion of sci­ence, tech­nol­ogy and pol­icy to pre­serve the planet and to improve the lives of the poor.

Glob­ally we have an out­stand­ing tech­ni­cal base to decar­bonize energy sys­tems to address issues from energy poverty to cli­mate change. But with­out equal atten­tion to the moral and long-​​term vision of the planet and soci­ety we want, how to use those resources remains unclear. While frack­ing may look, to some, to be a short-​​term panacea, a true energy and envi­ron­men­tal account­ing reveals the need to tran­si­tion from, not sim­ply extend, the reign of fos­sil fuels. With frack­ing under aggres­sive accel­er­a­tion in Argentina, Brazil, China, Mex­ico and else­where, we need that com­pass most urgently.

Daniel Kam­men, Berke­ley, Calif.

The writer is a pro­fes­sor of energy at the Uni­ver­sity of Cal­i­for­nia, Berke­ley, and found­ing direc­tor of the Renew­able and Appro­pri­ate Energy Lab­o­ra­tory (real​.berke​ley​.edu)